Modern wireless data communications provide bandwidth that allows user of wireless devices to use a number of rich mobile computing applications. For example, users of wireless devices such as smart phones can make telephone calls, receive emails, and even receive full motion audio/video broadcasts on their mobile devices. Every time a great new service is offered, users of wireless devices consume it and ask for more. As a result, the airwaves are filled with, and often packed with, data going to and from wireless computing devices.
The electromagnetic spectrum that wireless devices use for communication is treated as a precious resource. Governments control where in the spectrum particular wireless technologies can operate, and also control who can use particular portions of the spectrum (e.g., through high-cost spectrum auctions). Various mechanisms have been used to maximize the amount of data a network of wireless devices and corresponding base stations can put into a particular amount of spectrum. For example, multiplexing techniques may be used to stack multiple data streams in a single range of spectrum. Compression may also be used to transmit more data in a smaller data space.
Such techniques are at a premium when a large number of users want to use a particular communication system. Also, if a base station is to support a wide area (and thus reduce the number of base stations needed in a network), the base station will need to communicate with a large number of users at once. Such support for a large number of users who are all consuming large amounts of bandwidth can define the capability of a wireless communications system to compete.
Before wireless devices can communication application data with each other, they generally need to conduct what is sometimes known as a handshaking operation. Such an operation may involve the devices communicating their relative capabilities with each other so that subsequent communications can use a mode for which both devices are capable. For example, newer devices may be capable of communicating at higher data rates than are older devices, and the various devices may handshake to negotiate a highest mutual data rate for communicating. In other situations, a client device may indicate an initial need to a base station, and the two may communicate using that parameter until a new need is communicated.